Senior Staff Software Engineer (Engineering Lead)

Proximity Health is building a platform to unify and automate pharmacy revenue operations, focusing on the 340B program. They are seeking a Senior Staff Software Engineer / Engineering Lead to drive architectural evolution, define engineering standards, and lead a US-based team through complex technical challenges.

Responsibilities:

• Architect and implement scalable microservices using .NET Aspire and Azure Container Apps, ensuring reliable service discovery, resiliency, and operational simplicity
• Design hybrid cloud data strategies, managing complex ETL pipelines between AWS S3 and Azure Data Factory that handle terabytes of data with automated retries, resilience and binary copy resumption
• Define the 'Golden Path' for development, utilizing YARP as a strategic Backend-for-Frontend (BFF) to manage traffic routing, protocol upgrades, and legacy system strangulation
• Own the database architecture for high-load systems. Implement declarative partitioning (range/hash) strategies to maintain sub-millisecond query performance on datasets exceeding 1 billion rows
• Optimize Entity Framework Core and SQL queries to ensure efficient partition pruning, preventing I/O bottlenecks
• Manage the lifecycle of heavy data loads, ensuring zero-downtime migrations and non-blocking maintenance operations (e.g., VACUUM/ANALYZE)
• Implement eventual consistency patterns using MassTransit Sagas (state machines) to orchestrate complex, long-running business transactions across microservices
• Enforce the Transactional Outbox pattern to guarantee message reliability, idempotency, and correctness in an event-driven architecture
• Secure the infrastructure using Azure Private Link and VNet integration, ensuring critical data stores have no public exposure
• Build a world-class observability stack using OpenTelemetry (OTel), Azure Monitor, and Azure Managed Grafana
• Define Service Level Objectives (SLOs) and create dashboards that visualize saturation, latency, and error rates to proactively identify bottlenecks
• Lead the team through root-cause analysis and incident reviews, fostering a blameless culture that prioritizes systemic improvement over individual fault

Requirements:

• 10+ years of software engineering experience, including 3+ years in a Lead, Staff, Principal, or architecture-focused role
• Mastery of C# /.NET 8+, Azure (Container Apps, SQL, Service Bus, ADF), and AWS (S3 integration)
• Proven track record of scaling databases (PostgreSQL/SQL Server) to billions of rows. You can explain how you diagnosed and solved locking, bloat, or performance issues at scale
• Experience with complex backend integrations
• Knowledge of EDI standards (X12, NCPDP D.0) or healthcare claims processing is a major plus
• Demonstrated ability to lead remote teams, set best practices (RFCs, Code Review Standards), and mentor senior engineers
• Must be currently authorized to work in the United States without need for future sponsorship